Nairobi: A decomposed body found in a Kenyan river is not, as previously suspected, a man linked to the International Criminal Court`s case against Kenya`s Vice President William Ruto, police said Wednesday.

Instead, it appears the corpse belongs to another missing man, though police were going to use DNA testing to confirm its identity.

Meshack Yebei -- described by Ruto`s lawyer as a "critical" witness for the politician`s defence case -- remains unaccounted for.

Though Yebei`s family had initially positively identified the body as his, pathologists said its fingerprints belong to a missing man named Yusuf Hussein.

"The fingerprints do not belong to Yebei," said police detective John Kariuki, who added DNA testing would be done "so that we can come up with, 100 percent, who that person is."

Initial reports said Yebei disappeared December 28 and was found dead -- and badly mutilated according to some reports -- on January 4 in western Kenya`s Nandi district.

Ruto has been on trial at the ICC since September 2013 on charges of organising post-election violence in the east African country in 2007-2008. More than 1,200 people died and 600,000 were displaced in the chaos.

Ruto`s lawyer, Karim Khan, said in a letter seen by AFP that Yebei was a "critical witness to the defence" and had been referred to the ICC witness protection unit.

But the office of ICC chief prosecutor Fatou Bensouda last week said it had not called Yebei as a witness because, among other things, he "was deeply implicated in the scheme to corrupt prosecution witnesses in the case against Ruto and (co-defendant radio presenter Joshua Arap) Sang."

Kenya`s ICC investigations have been littered with allegations of witness intimidation, bribery and false testimony.

Charges against President Uhuru Kenyatta were dropped last month after the ICC prosecutor was ordered to strengthen or abandon the case.

Kenyatta maintained his innocence throughout and reacted by saying his conscience was "absolutely clear" regarding the post-election killings, the worst in Kenya`s history since winning independence from Britain in 1963.